1. Field of the Invention
This invention relates to a device for rapidly measuring the thickness of thin film deposited on the surface of a body by monitoring polarized light reflected from the surface of the body.
2. Description of the Prior Art
Ellipsometers have heretofore been used to analyse the surface of a body or thin film thereon. Most ellipsometers include a movable portion for mechanically rotating or sliding a polarizing plate or a phase plate. This approach has drawbacks, principally in that rapid measurement is difficult and inconvenient to achieve, particularly during so-called on-line measurement in which the thin film on a body is analysed in the course of a manufacturing process.